Near-Amorphous Semiconducting Polymers with Non-Covalent Interactions

High-performance semiconducting polymers with high charge carrier mobility and stretchability are desired for skin-like organic electronics. For conventional semi-crystalline semiconducting polymers, crystalline regions with π-π interactions are critical for interchain charge transport to endow good mobility, while it decreases mechanical stretchability. Near-amorphous polymers with high mobility, such as poly(indacenodithiophene benzothiadiazole) (IDTBT), brings in a new strategy of high-performance stretchable polymer semiconductors. The good charge carrier mobility is attributed to its rigid and coplanar backbone structure. Previously, various structural modifications on IDTBT have been studied, while most led to decreased mobility. In this work, non-covalent interactions, including S-F, S-O, and S-N, are introduced in IDTBT to further modify the backbone conformation and improve mobility performance. IDTBT derivatives are synthesized with optimized polymerization. The energy-favored backbone conformations are evaluated by computational simulation. The non-covalent interactions also influence energy levels, aggregation behaviors, and thin film morphology of IDTBT derivatives, which are related to their charge transport properties. High hole-mobility is obtained in top-gate bottom-contact field-effect transistors (FETs) for IDTBT with non-covalent interactions, which is further investigated with the low activation energy and disorder level. Stretchable FET devices are fabricated with the high-mobility IDTBT derivative and demonstrate good performance under strains.